Polypeptides comprising an ice-binding activity

Abstract

The present invention relates to novel polypeptides comprising an ice-binding capability resulting in an ice crystal formation and/or growth reducing or inhibiting activity. The present invention also relates to an edible product and to a solid support comprising the novel polypeptide. Furthermore, the present invention also relates to a method for producing the novel polypeptide and to different uses of the novel polypeptide.

What is claimed is: 
     
       1. A non-naturally occurring polypeptide having ice-binding activity, said polypeptide comprising 2 copies of ice-binding domain SEQ ID NO:73, 2 copies of ice-binding domain SEQ ID NO:74, 2 copies of ice-binding domain SEQ ID NO:75, 2 copies of ice-binding domain SEQ ID NO:76, 2 copies of ice-binding domain SEQ ID NO:77, 2 copies of ice-binding domain SEQ ID NO:78, 2 copies of ice-binding domain SEQ ID NO:79, and 2 copies of ice-binding domain SEQ ID NO:80, wherein the polypeptide comprises two regions, linked together covalently or non-covalently, each region comprising ice binding domains in the order SEQ ID NO:73, SEQ ID NO:74, SEQ ID NO:75, SEQ ID NO:76, SEQ ID NO:77, SEQ ID NO:78, SEQ ID NO:79 and SEQ ID NO:80. 
     
     
       2. The polypeptide according to  claim 1 , wherein the total number of amino acid residues of the polypeptide is less than 1000. 
     
     
       3. The polypeptide according to  claim 1 , wherein the total number of amino acid residues of the polypeptide is more than 100. 
     
     
       4. The polypeptide according to  claim 1 , wherein any two ice-binding domains are separated by at least 4 amino acid residues. 
     
     
       5. The polypeptide according to  claim 1 , wherein the polypeptide is linked to a carrier. 
     
     
       6. The polypeptide according to  claim 5 , wherein the carrier is a solid or semisolid support. 
     
     
       7. The polypeptide according to  claim 5 , wherein the polypeptide is covalently linked to said carrier. 
     
     
       8. The polypeptide according to  claim 5 , wherein the polypeptide is non-covalently linked to said carrier. 
     
     
       9. The polypeptide according to  claim 5 , wherein the polypeptide is displayed on a surface of said carrier. 
     
     
       10. The polypeptide according to  claim 1  operably fused to an N-terminal flanking sequence. 
     
     
       11. The polypeptide according to  claim 1  operably fused to a C-terminal flanking sequence. 
     
     
       12. The polypeptide according to  claim 1  operably fused to a signal peptide. 
     
     
       13. The polypeptide according to  claim 1 , wherein the polypeptide is fused to an affinity tag. 
     
     
       14. The polypeptide according to  claim 13 , wherein the affinity tag is selected from the group consisting of a His-tag, a polypeptide A tag, avidin/streptavidin, polypeptide G, gluthatione S-tranferase, dihyfrofolate reductase (DHFR), green fluorescent polypeptide (GFP), polyarginine, polycysteine, c-myc, calmodulin binding polypeptide, influenzavirus hemagglutinin; and maltose binding protein (MBP). 
     
     
       15. The polypeptide according to  claim 1 , wherein one or more amino acid residues are modified by acetylation, carboxylation, glycosylation, or phosphorylation. 
     
     
       16. The polypeptide according to  claim 1 , wherein the polypeptide is labelled with a detectable label. 
     
     
       17. The polypeptide according to  claim 1 , wherein the polypeptide is labelled with a fluorescently detectable label. 
     
     
       18. The polypeptide according to  claim 1 , wherein the polypeptide is a heterologous polypeptide produced by expression of a recombinant, non-host DNA molecule. 
     
     
       19. The polypeptide according to  claim 18 , wherein the non-host is selected from genus  Pichia.    
     
     
       20. A composition comprising a plurality of polypeptides according to  claim 1 , and a carrier. 
     
     
       21. A dried composition comprising a plurality of polypeptides according to  claim 1 . 
     
     
       22. The composition according to  claim 21 , wherein the dried composition is a freeze dried or spray dried composition. 
     
     
       23. A solid support comprising the polypeptide according to  claim 1 . 
     
     
       24. A solid support comprising the composition according to  claim 20 . 
     
     
       25. A method for inhibiting or controlling the formation of gas hydrates in the form of ice-like crystalline molecular complexes formed from mixtures of water and gas molecules, said method comprising the steps of
 i) providing a composition of polypeptides according to  claim 20 ; and 
 ii) contacting said composition with a mixture of water and gas molecules containing the gas hydrates; 
 
       thereby inhibiting or controlling the formation of the gas hydrates in said mixture of water and gas molecules. 
     
     
       26. A method for inhibiting or controlling the formation of gas hydrates in the form of ice-like crystalline molecular complexes formed from mixtures of water and gas molecules, said method comprising the steps of
 i) providing the solid support according to  claim 23 ; and 
 ii) contacting said said solid support with a mixture of water and gas molecules containing the gas hydrates; 
 
       thereby inhibiting or controlling the formation of the gas hydrates in said mixture of water and gas molecules.